Kotlin版本

val imm: InputMethodManager = getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
//Hide:
imm.toggleSoftInput(InputMethodManager.HIDE_IMPLICIT_ONLY, 0);
//Show
imm.toggleSoftInput(InputMethodManager.SHOW_IMPLICIT, 0);

只需在特定活动的AndroidManifest中添加以下行。

<activity
        android:name=".MainActivity"
        android:screenOrientation="portrait"
        android:windowSoftInputMode="adjustPan"/>

如果有人感兴趣的话，我已经为Kotlin写了一个小扩展，但没有太多测试：

fun Fragment.hideKeyboard(context: Context = App.instance) {
    val windowToken = view?.rootView?.windowToken
    windowToken?.let {
        val imm = context.getSystemService(Activity.INPUT_METHOD_SERVICE) as InputMethodManager
        imm.hideSoftInputFromWindow(windowToken, 0)
    }
}

App.instance是存储在Application中的静态“this”Application对象

更新：在某些情况下，windowToken为空。我增加了使用反射来检测键盘是否关闭的额外关闭方式

/**
 * If no window token is found, keyboard is checked using reflection to know if keyboard visibility toggle is needed
 *
 * @param useReflection - whether to use reflection in case of no window token or not
 */
fun Fragment.hideKeyboard(context: Context = MainApp.instance, useReflection: Boolean = true) {
    val windowToken = view?.rootView?.windowToken
    val imm = context.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    windowToken?.let {
        imm.hideSoftInputFromWindow(windowToken, 0)
    } ?: run {
        if (useReflection) {
            try {
                if (getKeyboardHeight(imm) > 0) {
                    imm.toggleSoftInput(0, InputMethodManager.HIDE_NOT_ALWAYS)
                }
            } catch (exception: Exception) {
                Timber.e(exception)
            }
        }
    }
}

fun getKeyboardHeight(imm: InputMethodManager): Int = InputMethodManager::class.java.getMethod("getInputMethodWindowVisibleHeight").invoke(imm) as Int

您可以使用下面的扩展来隐藏和显示软键盘

fun Fragment.showKeyboard(view: View) {
    view.isFocusableInTouchMode = true
    view.requestFocus()
    val imm = view.context?.getSystemService(Context.INPUT_METHOD_SERVICE) 
        as InputMethodManager
    imm.showSoftInput(view, InputMethodManager.SHOW_IMPLICIT) }

fun Fragment.hideKeyboard(view: View) {
    view.clearFocus()
    val imm = view.context?.getSystemService(Context.INPUT_METHOD_SERVICE) 
       as InputMethodManager
    imm.hideSoftInputFromWindow(view.windowToken, 0) }

要调用扩展，只需按照以下片段进行操作

showKeyboard(Your edittext ID)

hideKeboard(Your edittext ID)

如果你使用Kotlin开发你的应用程序，这真的很容易做到。

添加此扩展功能：

对于活动：

fun Activity.hideKeyboard() {
    val inputManager = getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
    val view = currentFocus
    if (view != null) {
        inputManager.hideSoftInputFromWindow(view.windowToken, InputMethodManager.HIDE_NOT_ALWAYS)
    }
}

对于片段：

fun Fragment.hideKeyboard() {
    activity?.let {
        val inputManager = it.getSystemService(Context.INPUT_METHOD_SERVICE) as InputMethodManager
        val view = it.currentFocus
        if (view != null) {
            inputManager.hideSoftInputFromWindow(view.windowToken, InputMethodManager.HIDE_NOT_ALWAYS)
        }
    }
}

现在，您可以简单地调用片段或活动：

 hideKeyboard()

我正在使用以下Kotlin Activity扩展：

/**
 * Hides soft keyboard if is open.
 */
fun Activity.hideKeyboard() {
    currentFocus?.windowToken?.let {
        (getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager?)
                ?.hideSoftInputFromWindow(it, InputMethodManager.HIDE_NOT_ALWAYS)
    }
}

/**
 * Shows soft keyboard and request focus to given view.
 */
fun Activity.showKeyboard(view: View) {
    view.requestFocus()
    currentFocus?.windowToken?.let {
        (getSystemService(Context.INPUT_METHOD_SERVICE) as? InputMethodManager?)
                ?.showSoftInput(view, InputMethodManager.SHOW_IMPLICIT)
    }
}